A 3-D staggered grid PSTD method for borehole radar simulations in dispersive media
三维错格时域伪谱法在频散介质井中雷达模拟中的应用

A finite difference time domain (FDTD) method is usually used to simulate borehole radar. However, it takes too much time and space for simulating a model with a relative large scale. A pseudospectral time domain (PSTD) method has the advantage of saving time and computer memory for the same simulation accuracy as that of FDTD. Thus we adopted a PSTD to simulate 3-D borehole radar in dispersive media. In order to suppress the Gibbs phenomenon of point source for PSTD, we set two points as sources in one direction and introduced a staggered grid. As an example for Debye dispersive media, we applied the second order Runge-Kutta method to the calculation in the time domain. This approach is stable for the media we are interested in. Comparing with the central time-differencing method, the approach adopted in this study is much easier for programming.